Low-fat dairy products

Green Tea

Drinking four cups of green tea a day helped people shed more than six pounds in eight weeks, the American Journal of Clinical Nutrition reports. Credit EGCG, a compound in the brew that temporarily speeds metabolism after sipping it. To up your intake, keep a jug of iced tea in the fridge. (Health)

Lentils

This superfood packs 35% of your daily iron intake in just one cup. Since 20% of us are iron-deficient, these are great to add to your diet. When your body lacks a nutrient like iron, your metabolism slows down.